intra-dimensional space I saw the glow of Tom Parker's force area and I made my way to your world quickly. But Tom could not get my warning: he was too stubbornly and deeply engrossed in the work he was engaged in. The girl Joan was slightly more susceptible, and I believe she was beginning to sense my telepathic messages when she sent for you. Still and all, I had begun to give up hope when you came on the scene. I took you away just as the spider men succeeded in capturing your friends, and now my hope has revived. I feel sure that my warning shall not have been in vain."

"But," objected Bert, "you've warned me, not the scientist of my world who is able to prevent the thing—"

"Yes, you," the Wanderer broke in. "It is better so. This Tom Parker is a zealot even as was I—a man of science thinking only of his own discoveries. I am not sure he would discontinue his experiments even were he to receive my warning in all its horrible details. But you, O Man-Called-Bert, through your love of his sister and by your influence over him, will be able to do what I can not do myself: bring about the destruction of this apparatus of his; impress upon him the grave necessity of discontinuing his investigations. You can do it, and you alone, now that you fully understand."

"Sa-ay! You're putting it up to me entirely?"

"Nearly so, and there is no alternative. I believe I have not misjudged you; you will not fail, of that I am certain. For the sake of your own kind, for the love of Joan Parker—you will not fail. And for me—for this small measure of atonement it is permitted that I make or help to make possible—"

"No, I'll not fail. Take me to them, quick." Bert grinned understandingly as the Wanderer straightened his broad shoulders and extended his hand.

There was no lack of substantiality in the mighty grip of those closing fingers.

Again the sphere's invisible motors increased speed, and again the dizzying kaleidoscope of color swept past them more furiously.

"We will now overtake them—your friends," said the Wanderer, "in the very act of passing between planes."

"Overtake them...." Bert mumbled. "I don't get it at all, this time traveling. It's over my head a mile."

"It isn't time travel really," explained the Wanderer. "We are merely closing up the time-space interval, moving to the precise spot in the universe where your friend's laboratory existed at the moment of contact between planes with your world and that of the Bardeks. We shall reach there a few seconds after the actual capture."

"No chance of missing?" Bert watched the Wanderer as he consulted his mathematical data and made new adjustments of the controls.

"Not the slightest; it is calculated to a nicety. We could, if we wished, stop just short of the exact time and would see the re-occurrence of their capture. But only as unseen observers—you can not enter the plane as a material being during your own actual past, for your entity would then be duplicated. Of course, I can not enter in any case. But, moving on to the instant after the event, as we shall do, you may enter either plane as a material being or move between the two planes at will by means of the gateway provided by Tom Parker's force area. Do you not now understand the manner in which you will be enabled to carry out the required procedure?"

"H-hmm!" Bert wasn't sure at all. "But this moving through time," he asked helplessly, "and the change from one plane of oscillation to another—they're all mixed up—what have they to do with each other?"

"All five dimensions of our universe are definitely interrelated and dependent one upon the other for the existence of matter in any form whatsoever. You see—but here we are."

The motors slowed down and a titanic page seemed to turn over in the cosmos with a vanishing blaze of magnificence. Directly beneath them glowed the disk of blue-white light that was Tom's force area. The sphere swooped down within its influence and came to rest.

"Make haste," the Wanderer said. "I shall be here in the gateway though you see me not. Bring them here, speedily."

On the one side Bert saw familiar objects in Tom's laboratory, on the other side the white cliff and the pitchy sea of the Bardek realm. And the cage of basket-weave between, with his friends inside struggling with the spider men. It was the instant after the capture.

"Joan! Tom!" Bert shouted.

A side of the sphere had opened and he plunged through and into the Bardek plane—to the inky surface of the sea, fully expecting to sink in its forbidding depths. But the stuff was an elastic solid, springy under his feet and bearing him up as would an air-inflated cushion. He threw himself upon the cage and tore at it with his fingers.

The whimpering screams of the spider men were in his ears, and he saw from the corner of his eye that other of the tortoiselike mounds were rising up out of the viscid black depths, dozens of them, and that hundreds of the Bardeks were closing in on him from all directions. Weapons were in their hands, and a huge engine of warfare like a caterpillar tractor was skimming over the sea from the cliff wall with a great grinding and clanking of its mechanisms.

But the cage was pulling apart in his clutches as if made of reeds. With Joan in one encircling arm he was battling the spider men, driving swift short-arm jabs into their soft bloated bodies with devastating effect. And Tom, recovering from the first surprise of his capture, was doing a good job himself, his flailing arms scattering the Bardeks like ninepins. The Wanderer and his sphere, both doomed to material existence only in infra-dimensional space, had vanished from sight.

A bedlam rose up from the reinforcing hordes as they came in to enter the force area. But Bert sensed the guiding touch of the Wanderer's unseen hand, heard his placid voice urging him, and, in a single wild leap was inside the sphere with the girl.

With Joan safely in the Wanderer's care, he rushed out again for Tom. Then followed a nightmare of battling those twining tentacles and the puffy crowding bodies of the spider men. Wrestling tactics and swinging fists were all that the two Earthlings had to rely upon, but, between them, they managed to fight off a half score of the Bardeks and work their way back into the glowing force area.

"It's no use," Tom gasped. "We can't get back."

"Sure we can. We've a friend—here—in the force area."

Tom Parker staggered: his strength was giving out. "No, no, Bert," he moaned, "I can't. You go on. Leave me here."

"Not on your life!" Bert swung him up bodily into the sphere as he contacted with the invisible metal of its hull. Kicking off the nearest of the spider men, he clambered in after the scientist.

The tableau then presented in the sphere's interior was to remain forever imprinted on Bert's memory, though it was only a momentary flash in his consciousness at the time: the Wanderer, calm and erect at the control panel, his benign countenance alight with satisfaction; Tom Parker, pulling himself to his feet, clutching at the big man's free arm, his mouth opened in astonishment; Joan, seated at the Wanderer's feet with awed and reverent eyes upturned.

There is no passing directly between the planes. One must have the force area as a gateway, and, besides, a medium such as the cage of the Bardeks, the orange light of the metal monsters, or the sphere of the Wanderer. Bert knew this instinctively as the sphere darkened and the flashing light-forms leaped across the blackness.

The motors screamed in rising crescendo as their speed increased. Then, abruptly, the sound broke off into deathly silence as the limit of audibility was passed. Against the brilliant background of swift color changes and geometric light-shapes that so quickly merged into the familiar blur, Bert saw his companions as dim